Navigation Links
Brain waves encode information as time signals
Date:12/16/2013

How information is processed and encoded in the brain is a central question in neuroscience, as it is essential for high cognitive function such as learning and memory. Theta-gamma oscillations are "brain waves" observed in the hippocampus of behaving rats, a brain region involved in learning and memory. In rodents, theta-gamma oscillations are associated with information processing during exploration and spatial navigation. However, the underlying synaptic mechanisms have so far remained unclear. In research published this week in the journal Neuron, postdoc Alejandro Perna-Andrade and Professor Peter Jonas, both at the Institute of Science and Technology Austria (IST Austria), discovered the synaptic mechanisms underlying oscillations at the dentate gyrus (main entrance of the hippocampus). Furthermore, the researchers suggest a role for these oscillations in the coding of information by the dentate gyrus principal neurons. Thus, these findings contribute to a better understanding of how information is processed in the brain.

Brain oscillations are, in fact, rhythmic changes in voltage in the extracellular space, referred to as electrical brain signals associated with the processing of information. These electrical signals are similar to those seen in electro-encephalographic recordings (EEG) in humans. Perna-Andrade and Jonas observed these oscillations in a brain region called the hippocampus in behaving rats, and recorded oscillations occurring in this area using extracellular probes. To understand how oscillations are generated and which synaptic events trigger these oscillations, the researchers looked at synaptic transmission in granule cells (principal cells at the main entrance of the hippocampus) from both the extracellular (oscillations) and the intracellular perspectives (synaptic currents and neuronal firing), and then correlated the two. They discovered that excitatory and inhibitory synaptic signals contributed to different frequencies of oscillations, with excitation from the entorhinal cortex generating theta oscillations and inhibition by local dentate gyrus interneurons generating gamma oscillations. Together, excitation and inhibition provide the rhythmic signals of oscillations. It has been speculated that oscillations may help the dentate gyrus to encode information by acting as reference signals in temporal coding. Perna-Andrade and Jonas now show that granule cell neurons send signals only at specific times in the cycle of oscillations. This so-called "phase locking" is necessary if oscillations are to function as reference signals in temporal coding.

The precise, high-resolution recording from granule cells necessary for these discoveries was possible only through technological innovations by Perna-Andrade and Jonas, as previously no equipment was available to record synaptic signals in active rats in such high resolution. They are the result of a collaboration with the Miba machine shop, IST Austria's electrical and mechanical SSU (Scientific Service Unit). Adapting commercially available equipment and custom-designing tools, Perna-Andrade, Jonas and Todor Asenov, manager of the Miba machine shop, produced the first tools for precise biophysical analysis in active rats. This research is therefore not only a scientific advance but also represents a significant technological and conceptual progress in the quest to understand neuronal behavior under natural conditions.


'/>"/>

Contact: Oliver Lehmann
oliver.lehmann@ist.ac.at
43-022-439-000-1006
Institute of Science and Technology Austria
Source:Eurekalert  

Related biology news :

1. Study breaks blood-brain barriers to understanding Alzheimers
2. Dietary amino acids improve sleep problems in mice with traumatic brain injury
3. Gene found to be crucial for formation of certain brain circuitry
4. TGen, Barrow and PCH receive $4 million grant to study genetic basis of brain injuries
5. Alzheimers risk gene may begin to affect brains as early as childhood, CAMH research shows
6. New compound for slowing the aging process can lead to novel treatments for brain diseases
7. Neurofeedback tunes key brain networks, improving subjective well-being in PTSD
8. Prenatal exposure to alcohol disrupts brain circuitry
9. New UK study suggests low vitamin D causes damage to brain
10. An abnormal resting-state functional brain network indicates progression towards AD
11. Swarming insect provides clues to how the brain processes smells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Brain waves encode information as time signals
(Date:4/11/2017)... , Apr. 11, 2017 Research and Markets ... 2017-2021" report to their offering. ... The global eye tracking market to grow at a CAGR ... Global Eye Tracking Market 2017-2021, has been prepared based on an ... the market landscape and its growth prospects over the coming years. ...
(Date:4/5/2017)... April 5, 2017  The Allen Institute for Cell ... Explorer: a one-of-a-kind portal and dynamic digital window into ... data, the first application of deep learning to create ... cell lines and a growing suite of powerful tools. ... these and future publicly available resources created and shared ...
(Date:4/3/2017)... , April 3, 2017  Data captured ... engineering platform, detected a statistically significant association ... prior to treatment and objective response of ... potential to predict whether cancer patients will ... treatment, as well as to improve both pre-infusion ...
Breaking Biology News(10 mins):
(Date:8/16/2017)... ... 2017 , ... Tunnell Consulting announced today that four of the ... Meeting and Expo , to be held October 29 through November 1 in San ... to advance patient therapies.” , The ISPE Annual Meeting and Expo will feature several ...
(Date:8/16/2017)... ... August 16, 2017 , ... ... a different cell type. Many treatments for specific cancers, such as breast, prostate, ... targeted treatment is androgen deprivation therapy for advanced prostate cancer. , This ...
(Date:8/16/2017)... ... August 16, 2017 , ... Today, ... announced it has secured $2M in funding from an impressive group of investors, ... and SVG Thrive Fund. With this investment, 3Bar is broadening availability of its ...
(Date:8/16/2017)... edition of the Inc. 5000 features a now-familiar name: BioPoint ( http://biopointinc.com/ ... list for the third year in a row. Now in its 36th ... a set of quantitative metrics. In addition, BioPoint was also named to ... Bay State . ... ...
Breaking Biology Technology: